In Subversion, why is there a copy of trunk in my tagged revision?

My project is set up in Subversion with the standard trunk / branches / tags structure. I created a tag with a copy command like so:

svn copy /path/to/project/trunk /path/to/project/tags/cya_tag 

This creates a copy just as I expected, but I can also see a new directory /project/tags/cya_tag/trunk that contains another copy of the trunk.

My guess is that this copy is used to track where the tagged version branche开发者_开发技巧d off of the trunk, but I can't find any documentation anywhere that states this. Am I right?

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For svn /branches or /trunk is a common directories as any other. It doesn't process them in any special way. Somebody maybe has executed to get what you see:

svn copy /path/to/project/ /path/to/project/tags/cya_tag 

To understand this check svn log:

svn log /path/to/project/tags/cya_tag